1. Field of the Invention
This disclosure is related to the field of devices and methods for providing intermittent flow in a vessel, particularly intermittent flow in a baby bottle to assist in teaching preterm infants to successfully eat.
2. Description of the Related Art
The average gestation period of a human being is generally considered to be 280 days, or around 40 weeks. Recent science has indicated that birth, without any medical intervention or complications of preterm birth, will, on average, occur at a little over 38 weeks after fertilization. Generally, an infant born from 37-42 weeks after conception is considered to be “full term.” A large number of babies, however, are born prior to this period. In the United States around 12% of babies born each year are considered to be “preterm,” that is, before the 37th week. Some of these births occur spontaneously, some occur due to complications in pregnancy, others are scheduled early due to the need for planned Cesarean section births, some are due induced labor following abnormal lab results, and others from concern that an infant is getting too large to be easily delivered.
Regardless of the reason that an infant is born preterm, preterm infants (and even those born in the 38th and 39th week compared to those born later) generally have more medical issues at birth than full term infants. For example, infant mortality rates for preterm infants are generally double those of full term infants. Another problem associated with preterm babies is that they have trouble learning how to eat. The act of nursing (or alternatively eating from a bottle) generally requires an infant to follow a pattern usually referred to as “suck-swallow-breathe.” In this pattern, an infant sucks once, swallows once, breathes once, and then repeats. Preterm infants, however, may feed with repetitions of 3 or 4 (or more) sucks and swallows and 1 breathing break. However, many preterm infants have trouble maintaining any pattern and an inability to feed can lead to further complications with the infant; this can result in increased medical expense because of the need to keep them at a hospital.
Because many preterm infants (and particularly very early preterm infants) are maintained in a Neonatal Intensive Care Unit (NICU), they are often bottle fed (breastfeeding is a challenge) and effective feeding patterns must be imposed until the central nervous system matures to enable coordination of the suck-swallow-breathe pattern. While preterm infants often demonstrate adequate suction and compression on the bottle to express milk very early in gestation, the immature central nervous system does not signal the infant to pause for respiration, which results in inadequate oxygen in the blood and dangerous drops in heart rate. In the months prior to term equivalent age, cautious caregivers can promote an imposed breathing break by allowing the infant to take a few sucks from the bottle followed by pulling the bottle out of the infant's mouth. This procedure requires special expertise and considerable time, causes the infant significant energy expenditure and physiological stress, and disrupts the feeding process. The complexities of feeding infants delay discharge and increase hospital costs. NICU nurses and therapists currently manually pace preterm infants during bottle feeding, and parents are often taught how to pace preterm infants during oral feeds. It has been found that many preterm infants will continue sucking until prompted to swallow and breathe by the feeder. During feeding, monitors attached to the infants in the NICU collect data regarding respiration, heart rate and other vital signs to assist the nurse in knowing when to prompt the infant to swallow and breathe. However, these monitors often take longer to alert a nurse than desired. This requires the nurse to analyze the infant's facial features for signs of stress, such as raised eyebrows, breathing difficulty, or blue discoloration.
When the NICU nurse detects that the infant needs to breathe, the nurse tilts or, if necessary, completely removes the bottle to stop the flow of liquid from the bottle. This cues the infant to swallow and begin breathing again. This system is highly subjective to human intervention and requires constant attention during feeding to minimize the possibility of risks such as choking or aspiration. Many infants will eventually pick up the rhythm of suck-swallow-breathe after only a few repetitions, and it is desirable for infants that quickly pick up the pattern to begin pacing naturally as that allows them to maintain their own pattern and maintain their own pace while maximizing the amount of intake. Removing or maneuvering the bottle can often cause problems with the infant establishing a pattern, gaining an adequate swallow on fluid that has been expressed, and/or re-establishing the feeding response. Therefore it is desirable to provide a more simplified solution for establishing an eating pattern.